1. Tuesday July 20, 2011
Hubbs Center - Math 2
Agenda and Objectives

2. Today’s Objectives...
 We will complete a real world math
problem to show what we know about
fractions.
 We will take notes on what we have
learned to do with fractions.
 We will practice how to borrow when
subtracting with fractions.
 We will practice word problems that
require the addition and subtraction of
fractions.

3. Real World Math Problem
 Joannabought 1 2/9 of a pound of
chocolates and ate 1/6 of a pound. How
much was left?
 Anton bought a board that was 3 4/5
yards long. He cut off 1/2 of a yard.
How much was left?

5. Fractions Notes
 Rules for Adding Fractions:
1. Make sure the denominators are the
same
2. Add the numerators. Put the answer over
the same denominator.
3. Simplify (reduce) the fraction, if possible.
– Example: 12/13 + 1/2

6. Fractions Notes
 Rules for Subtracting Fractions:
1.Change mixed numbers to improper
fractions.
2.Make sure the denominators are the same.
3. Subtract the numerators. Put the answer
over the same denominator.
4. Simplify (reduce) the fraction, if possible.
 Example: 5/8 - 1/10

7. Fractions Notes
 How to change an improper fraction into
a mixed number:
 How to change a mixed number into an
improper fraction:

8. Fractions Notes
 How to find a common denominator so
you can add or subtract:
 Example: 3/7 + 5/8
1. List the multiples for both denominators (multiply the number x1, x2, x3...)
2. Find the smallest multiple they have in common (the same).
3. Multiply each fraction, top and bottom, to get that multiple.
4. Add or subtract the numerators.
Remember:
What you do to the bottom of the fraction,
You have to do the same to the top!

9. How to reduce or simplify fractions
 To simplify a fraction, divide the top and
bottom by the highest number that can
divide into both numbers exactly.
 Example: 24/108
from: http://www.mathsisfun.com/simplifying-fractions.html

10. How to borrow when you subtract fractions
 First, think about how you solve: 25
-17
 Next, think about how you might solve:
3 1/3 - 1 2/3

11. Addition and Subtraction Word Problems
 HW Sample Problems: